JPS6038205Y2 - Closed type torque/thrust measuring device - Google Patents

Description

[Detailed description of the invention] This invention is a closed-type torque/thrust measurement device that can accurately measure the torque and thrust of a rotating shaft for driving a load in a pressurized atmosphere, such as underwater, without being affected by changes in water pressure. It is related to the device.

When measuring the torque or thrust of a rotating shaft, a strain gauge, for example, is used as a detector, and these detectors are equipped with an electric circuit for obtaining an electric output proportional to the applied force.

Therefore, if the measuring device must be located underwater in an atmosphere where its operation is inhibited, for example when detecting the torque of a rotating shaft underwater, it is necessary to isolate the detector from the water. be.

Therefore, a closed type measuring device as shown in the sectional side view shown in FIG. 1 has been conventionally used.

In Figure 1, 1 is a case, 2 is a driving shaft, 3 is a torque detector such as a strange gauge, 4 is a coupling with a mechanism that is free for thrust, 5 is a load shaft, and 6 and 7 are for waterproofing. The seals are interposed between both ends of the case 1 and the drive-side shaft 2 and load-side shaft 5 to prevent water from entering.

A rolling bearing 8 supports the driving shaft 2.

9 is a slip ring, and 10 is a waterproof connector. The slip ring 9 takes out the electrical output of the torque detector 3 that rotates together with the driving shaft 2, connects it to the waterproof connector 10, and connects it to the waterproof cable (not shown) connected here. and supply it to the measuring instrument.

A metal bearing 11 supports the load-side shaft 5 so as to be free from the thrust of the shaft.

12 is a thrust transmission mechanism, 13 is a connecting body, 14 is a thrust detector such as a strain gauge, and the thrust transmission mechanism 1
2 applies only the thrust of the shaft to the thrust detector 14 via the connecting body 13 without interfering with the rotation of the shaft.

The electrical output is then connected to the above-described waterproof connector 10 and connected to a measuring instrument using the above-described waterproof cable.

This device transmits the rotational force of a drive-side shaft 2 coupled to a drive source side to a load-side shaft 5 connected to a load via a torque detector 3 and a coupling 4. 3, the torque T shown by arrow A in the figure can be detected, and at this time, the thrust T2 shown by arrow B in the figure transmitted to the load side shaft 5 can be detected by the thrust detector 14.

However, this device has the disadvantage that significant measurement errors occur, primarily due to the presence of the waterproof seal.

That is, as is well known, waterproof seals have large friction.

Therefore, when this exists on the load shaft side, not only is it difficult for the true torque and thrust transmitted from the load side shaft to the load to be transmitted to the detector, but also the friction changes depending on the rotation speed, causing the torque value to change. Because of this, measurement errors are likely to occur.

For example, as the depth of the water where this measuring device is located increases, the water pressure increases, tightening the waterproof seal and increasing the frictional force with the load shaft, making it difficult to obtain true torque and thrust values. Not only is it difficult to do this, but the measured values of thrust torque, etc., will fluctuate due to changes in the water depth at which the measuring station is located, and measurement errors caused by these are generally extremely large.

Therefore, it is difficult to perform accurate measurements with this measuring device.

The purpose of the present invention is to provide a closed-type torque/thrust measuring device that eliminates all the drawbacks of the conventional devices as described above, and the details thereof will be explained below with reference to the drawings.

FIG. 2 is a cross-sectional side view showing one embodiment of the present invention, in which 15 is a case, 15' is a load side shaft through hole, (1
The case portion indicated by 6 may be omitted.

) 17 is a drive side shaft, 18 is a drive cylinder, 18' is a load side shaft through hole, and the drive cylinder 18 is formed integrally with one end of the drive side shaft 17 so as to be coaxial therewith.

A rolling bearing 19 rotatably supports the driving shaft 17 in the case 15.

20 is a waterproof seal, and 21 is a slip ring, to which electrical outputs of detectors 24 and 26, which will be described later, are connected.

22 is a waterproof socket for taking out the output of the slip ring 21, and the waterproof seal 20 makes the storage space 15'' of the slip ring 21 watertight.

23 is a load side shaft, 24 is a torque detector such as a strain gauge, and 25 is a coupling body, one end of which is fixed to the other end of the torque detector 24 fixed to the inner surface of the drive cylinder 18.

Reference numeral 26 denotes a thrust detector, such as a strange gauge, which is fixed between the joint 25 and the circumferential surface of the load-side shaft 23 and is configured to detect only thrust regardless of torque.

Further, the load-side shaft 23 and the drive-side shaft 17 are connected coaxially by the detectors 24, 26 and the combination body 25.

Reference numerals 27 and 28 denote first and second bellows, which have the same effective area, are free from thrust, and are constructed to be sufficiently resistant to external pressure.

Then, the drive cylinder 18
The torque and thrust detectors 24 and 26 are airtightly installed between the load-side shaft 23 and the installation space 18'' to have a watertight structure.

Reference numeral 29 denotes a through hole for pressure balance, and the case 15 and drive cylinder 18 communicate with the external atmosphere via the load side shaft through hole 15'.
The space between them is communicated with the internal space 27' of the first bellows 27 to make the air pressure in the bellows internal space 27' equal to the outside air pressure.

The output wires of the torque and thrust detectors 24 and 26 are connected to the slip ring 21 through a pull-out hole (not shown) provided in the drive cylinder 18 and the drive shaft 17, and the output of the slip ring 21 is waterproof. It is connected to the socket 22 and connected to the measuring instrument via a waterproof cable.

In the present device having such a configuration, the waterproof seal 20 is only on the drive side shaft 17 side and is not on the load side shaft 23, so the rotational force of the drive side shaft 17 is transmitted to the drive cylinder 18 and the torque detector 24. The rotational force is faithfully transmitted to the load-side shaft 23 via the coupling body 25 and the thrust detector 26, and is also transmitted to the load-side shaft 23 via the 11th and second bellows 27, 28, so that torque and thrust are measurements are taken.

In this), the torsion constants of the first and second bellows 27.28 are:
It is much smaller than that of the torque detector 24, and the spring constants of the first and second bellows 24, 28 are also much smaller than that of the thrust detector 26.

Therefore, torque and thrust can be measured without being affected by the eleventh second bellows 27,28.

Moreover, in the present device, the first and second bellows 27.2
8 have the same effective area, and in addition to this, a through hole 29 for air pressure balance is provided to make the voltage in the internal space 27' of the first bellows 27 the same as the outside water pressure.

Therefore, the thrust generated in the first bellows 27 due to the external water pressure from the internal space 27' side and the thrust generated in the second bellows 28 due to the external water pressure from the outside cancel each other out. It is not affected by such fluctuations.

Of course, there is no structural effect on torque.

As described above, in this case, the waterproof seal 20 is provided only on the drive side shaft 17 side, so that torque etc. are faithfully transmitted to the load side shaft 23, and the drive cylinder body 18 is provided on the drive side shaft 17, and the inside thereof is A torque detector is housed in the space, and the housing space has a watertight structure with bellows designed so as not to affect the detection of torque or thrust.

Therefore, conventional methods that use waterproof seals to create a watertight structure inside the case can cause large friction on the load-side shaft, resulting in inaccurate measurements, or fluctuations in the frictional force due to fluctuations in water pressure can cause the measured values to There is no possibility that the measurement will be inaccurate due to variations in the measurement results.

In the above description, the case of measurement in water has been described, but similar effects can be obtained by using it for measuring torque and thrust of a rotating shaft in various atmospheres having pressure fluctuations.

As is clear from the above explanation, according to the present invention, it is possible to provide a closed-type torque-thrust measuring device that can accurately measure the torque, thrust, etc. of the rotating shaft without being affected by the atmospheric pressure of each part, and is suitable for practical use. The effect is great.

[Brief explanation of drawings]

FIG. 1 is a sectional side view showing a conventional device, and FIG. 2 is a sectional side view showing an embodiment of the present invention. 15... Case, 15'... Load side shaft through hole, 15''... Slip ring accommodation space,
16... Case parts that may be removed, 17...
...Drive side shaft, 18...Drive cylinder body, 18'
...Load side shaft through hole, 18''...Detector installation space, 19...Rolling bearing, 20.
... Waterproof seal, 21 ... Slip ring, 22 ... Waterproof socket, 23 ...
・Load side shaft, 24...Torque detector, 25...
... Combined body, 26 ... Thrust detector, 2
7, 28...First and second bellows, 27'...
...inner space of the first bellows, 29... through hole for pressure balance.

Claims (1)

[Scope of utility model registration request] It is rotatably supported by the case and sealed with a waterproof seal, and the slip ring installation part for taking out the output of the torque/thrust detector is driven to one end of the drive side shaft with a watertight structure. A cylindrical body is provided, and inside the driving cylindrical body, one end is fixed to a torque detector on the inner surface thereof, and the other end of a thrust detector is fixed at one end via a coupling body. The load-side shafts are connected so that A second bellows having the same characteristics as the first bellows is provided to make the torque and thrust detector installation space in the drive cylinder watertight, and the first bellows is provided with a pressure balance for communicating the internal space with the external atmosphere. Through-holes are provided to allow torque and torque to be achieved without being affected by the external atmosphere.
A sealed torque/thrust mounting device that can measure thrust.